1. Field of the Invention
The present invention relates to an optical transceiver with a pluggable function, in particular, the invention relates to the optical transceiver installing a bi-directional optical sub-assembly with a single package.
2. Related Background Art
A bi-directional optical sub-assembly (hereinafter denoted as BOSA) has been developed and is now installed in the optical transceiver. Such a BOSA enables to transmit an optical signal to an optical fiber and to receive another optical signal from the optical fiber concurrently by differentiating the wavelengths to each other. The United States Patent published as US-20060039657A has disclosed one type of BOSAs, in which the optical transceiver installs a transmitter optical device and a receiver optical device having individual packages are assembled in a transceiver body where a wavelength division multiplexing filter (WDM filter) is provided. This type of the BOSA is called as the multi-packaged BOSA. While, the United States Patent, U.S. Pat. No. 7,309,172, has disclosed another type of the BOSA which installs the light-emitting device, the light-receiving device and the WDM filter within a single package, which is called as the single-packaged BOSA.
Because the single-packaged BOSA encloses both the light-emitting device and the light-receiving device immediately close to each other, it should be taken the crosstalk between the transmitter unit and the receiver unit, especially, the crosstalk from the transmitter unit to the receiver unit into account. Further, because the single packaged BOSA installs many devices in the single package compared to the multi-packaged BOSA, which increases the heat generated by the devices, the thermal stability of the BOSA should be also considered.
The present invention is to provide an optical transceiver with the single-packaged BOSA that improves both the noise characteristic including the crosstalk performance and the heat dissipation.